This is a breaking news story. Check back for updates.
UPDATE 10:56 a.m. EST: A transformer is believed to be the source of the fire. Someone who lives near the power plant reported hearing a "loud, ground-shaking explosion and then saw smoke," according to Russellville newspaper the River Valley Leader.
A fire and possible explosion rocked a nuclear plant Monday morning in Arkansas.
A spokeswoman for the Arkansas power company Entergy told the paper that the fire is “contained.”
Meanwhile, reports of an explosion at the nuclear plant were reported by the Twitter breaking news account @PzFeed.